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UNITED STATES PATENT OFFICE.

PATRICK B. 'DELANY, OF NEW YORK, N. Y., ASSIGNOR To THE STANDAR MULTIPLEX TELEGRAPH COMPANY, OF SAME PLACE.

SYNCHRONOUS TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 322,427, dated July 21, 1885.

Application filed February 29, 1884'.

To all whom it may concern:

Be it known that I, PATRICK B. DELANY, of the city, county, and State of New York, have invented certain new and useful Improvements in Telegraphy, of which the fol lowing is a specification.

My invention relates, generally, to that class of telegraphic systems in which the transmitting-current is made up of a series of rapid vibrations or impulses, and in which each signal is made by the action of a number of such impulses or vibrations, or in which such rapid impulses are utilized to actuate stepby-step mechanism, as in printing-telegraphs. It specially relates to the system of synchronous telegraphy disclosed in Letters Patent granted to me on the 9th of October, 1883.

The object of the invention is, primarily, to prevent chattering or Vibration of the receiving-armature on its contacts; and this I accomplish by the use of condensers.

I am aware that 011 long cables condensers have been employed and placed between the cable and the receiving-instruments and between the cable and the transmitting-instruments, and I therefore make no claim to such broad ground. I am also aware of the British patent of Varley, No. 1,044, of April 8, 1870, in which condensers are used in connection with undulatory or vibratory currents, each receivinginstrument being thrown into vibration by the fundamental sympathy of that instrument for the particular group of vibrations transmitted over the line for the purpose of actuating it.

The subject-matter of my invention is fully set forth below.

Theaccompanying drawing isadiagramview illustrating two connected stations organized according to my invention.

In several Letters Patent of the United States granted to me October 9, 1883, I have shown an arrangement of correcting contacts such as illustrated in the drawing. I have also in said patents fully described and illustrated means by which the trailing finger a at each station is caused to rotate synchronously over the table A of contacts.

The several Letters Patent above referred to illustrate several different ways of maintain- (No model.)

ing the synchronous movement of the circuit com pleters at each end of the line, any one of which may be adopted in the present case.

In Letters Patent No. 286,278, of October 9, 5 5 1883, I have shown a table of sixty contacts, numbered, in six series, from 1 to 10, the 9s and 10s being devoted to synchronous correction, thus leaving six groups of eight contacts each devoted to telegraphic purposes. In that patent I have also illustrated and described the manner in which these contacts could be connected up into independent circuits for multiplex transmission, so that as the trailing fingers rotate synchronously at each station each independent circuit would be completed about thirty-four times a second, so that the trans mitting-current for each circuit was made up of a series of rapid impulses or vibrations.

In the present case I have shown a table of .70 sixty contacts, and they may be connected in the same way. It is therefore unnecessary to elaborate the drawing or enter into any detailed description of that arrangement.

It has been deemed sufficient to show in the drawing telegraphic apparatus connected with onecontact at one station and telegraphic apparatus connected with the corresponding contact at the other station. It will of course i be understood that any desired number of .8 working-contacts may be-connected in circuit with this contact at each station, so that as the trailing fingers rotate at each station the circuit from the instruments at one station to those at the other will be rapidly made and broken at the rate of about thirty-four impulses (more or less) per second. Signals transmitted over such a vibratory circuit, when received upon ordinary instruments, or even upon polarized relays, are liableto beimperfect on account of the chattering or singing of the receiving-armature on its contact, caused by the makes and breaks in the circuit.

The object of my invention is to overcome this difficulty, and provide an effective means whereby the signals may be received distinctly and sharply and with perfect accuracy.

While, as above remarked, this invention is designed by me for use specially in connection with my improved system of synchronous telegraphy, it may be used in any system in which signals or impulses of electricity are transmitted by means of a vibratory current or one made up of fine impulses.

Between the contacts at each station andthe receiving polarized relay R, I place a condenser, O D. Each line is also equipped with an ordinary reversing transmitting-key, battery, and switch. Assuming that on the circuit illustrated a message is being transmitted from X to Y, the manipulation of the key K alternately puts the opposite poles of the split battery S B to line, thus creating alternating electrostatic conditions in the condensers and operating the polarized relay at station Y, causing it to respond to the working of the key at X. WVhile the key K is on one pole of the battery in the operation of making a signal the circuit will be completed from the same pole of the battery a number of times; but the impulses after the first will not affect the receiving-relay armature, which-remains in the position into which it is drawn until a reversal of the current is effected, because no change in the electric condition of the line can takeplace until the opposite pole of the battery is put to the line. The succeeding impulses, therefore, beyond the first one required to affect the condensers and the receiving-relays, being of the same polarity,will not occupy the line to any extent. On the contrary, in the ordinary system,in the formation of a letter over an interrupted circuit, ten or twelve pulsations (more or less) might be transmitted direct from the battery-that is, successive pulsations would be transmitted so long as the operators key remained closed upon the front stop, and also on the back stop when working with reversed batteries,ther'eby loading the line with numerous impulses. By the use of condensers,owin g to the conditions above mentioned, the ordinary static charge of the line is lessened, and effects of earth or other currents are greatly or entirely overcome, for the reason that there is no metallic continuity of the line. The intensity of the current from the condenser is greater than the ordinary battery-current, and manifests its charge more quickly at the distant end of the line. The variable period of the line is therefore lessened, and the armatures of the receiving-relays move with great quickness and precision.

At station Y, I have shown an ordinary arrangement for transmission from a single pole of the battery 13. Under this arrangement the electrostatic conditions created by the condensers are alternated by the alternate connection of the line with the ground and battery. In practice I would of course prefer to have the organization at each station alike.

The two arrangements have been shown in the diagram for convenience of illustration merely.

The condensers are shown as located betweeen the main line and the receiving-relays. They might, however, be located between the instruments and the ground. The mere location is immaterial, so far as my invention is concerned.

My invention may be worked with advantage witha condenser placed at either end of the line or somewhere in the circuit. I prefer, however, to place condensers at both ends of the line, as described.

I claim as my invention 1. The combination of an electric circuit, a condenser or condensers therein, a source of electric energy, means, substantially such as described, for rapidly interrupting the circuit or subdividing the transmitting-current into a number of distinct impulses, transmitting devices, and receiving devices consisting of a magnet or magnets and a rocking or vibrating armature, each actuation of which constitutes a distinct signal or determinate portion thereof, the arrangement being such that each of said unitary signaling movements occurs while a group of said distinct electrical impulses is sent into the line.

2. The combination, with a system of telegraphy in which during the formation of each are sent into the line, of one or more c011- densers in the circuit, transmitting-instruments, and a receiving-instrument consisting of a magnet or magnets and a rocking or vibrating armature which makes one unitary movement in response to each group of impulses sent into the line.

3. The combination, in a system of telegraphy in which the transmitting-current is divided into a number of distinct impulses, of an electric circuit, one or more condensers therein, transmitting devices, and means whereby a number or group of said distinct impulses are sent into the line for the transmission of a unitary signal, and receiving devices consisting of a magnet or magnets and a rocking or vibrating armature which makes one unitary movement in response to each group of impulses sent into the line.

4. The combination, in a system of teleg raphy in which the transmitting-current is divided into a number of distinct rapid impulses, of an electric circuit, one or more condensers therein, telegraphic transmitting-instruments, and receiving polarized relays.

5. The combination, in a system of telegraphy in which the transmitting-current is divided into a number of distinct rapid impulses, of an electric circuit, telegraphic transmitting-instruments and polarized relays at each end of the line, and a condenser at each end of the line interposed between said relays and the main line.

6. The combination, substantially as set forth, of a main line, synehronously-actuated apparatus at each end of the main line, a table of contacts with which the line is successively momentarily connected by the rotation of said synchronous apparatus at each end of the line, telegraphic transmitting-instruments at one station connected with one or more of said independent contacts, receivirig-instruments at the other station connected with the corre sponding one or more contacts at that station,

and one or more condensers in the circuit of polarized receiving-relay at the other station W said transmitting and receiving instruments. connected with the one or more correspond- 7. lhe combination, substantially as set ing contacts at that station, and a condenser I 5 forth, of a main line, synchronously-actuated in circuit with said receiving-relay.

5 apparatus at each end of the main line, a se- In testimony whereof I have hereunto subries of independent contacts with which the scribed my name this 20th day of February, main line is successively momentarily con- A. \D. 1884. p nected by the rotation of the synchronous apparatus at each station, telegraphic transmit- PATRICK DELANY' 1o ting apparatus at one station connected with Witnesses:

one or more of said contacts, a condenser in EDWD. A. CALAHAN, circuit with said transmitting-instruments and FRANK W. J ONES. 

